update HTML pages as per recent commits

2024/burton/index.html

@@ -441,7 +441,7 @@
 <!-- START: this line starts content from: inc/navbar.mid.html -->
 
 <div class="navbar">
-  <a class="Left" href="../anders/index.html">&larr; 2024/anders</a>
+  <a class="Left" href="../../2020/yang/index.html">&larr; 2020/yang</a>
   <a class="Left" href="../index.html">&uarr; 2024 &uarr;</a>
   <a class="Left" href="../cable1/index.html">2024/cable1 &rarr;</a>
   <a class="Right" href="https://github.com/ioccc-src/winner/blob/master/2024/burton/prog.c">C code</a>